Method for interplanting energy crops

ABSTRACT

In methods according to some embodiments of the present disclosure for interplanting a primary crop and an energy crop, the present disclosure includes methods for preparing a plantation site for planting the energy crop. Plantation sites according to the disclosure may include a primary crop planted in a first row and in a second row, the first row being separated by an intermediate area. The intermediate area is divided into a center portion and two side portions (a first side portion and a second side portion). Methods according to embodiments of the disclosure include lifting a soil and plantation debris mixture from the intermediate area, and redepositing a soil component of the soil and plantation debris mixture primarily in the intermediate area.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/309180, filed Dec. 1, 2011, which claims the benefit of U.S.Provisional Application No. 61/421129, filed Dec. 8, 2010, thedisclosures of which are hereby expressly incorporated by referenceherein in their entirety.

This application relates to U.S. application Ser. No. 13/309214, filedDec. 1, 2011, and titled “Soil Treating System and Shearing Assembly,”the disclosure of which is hereby expressly incorporated by referenceherein in its entirety.

TECHNICAL FIELD

The present disclosure is directed generally to methods forinterplanting energy crops with a primary crop on a plantation site.

BACKGROUND

Due to diminishing quantities of coal, petroleum, and natural gasproducts, attention is being directed to other energy sources, includingoil shale, solar energy, and nuclear energy. One source receivingconsiderable attention is forest biomass materials such as wood, plantsgrown in conjunction with trees, and wood byproducts. Forest biomass mayinclude any type of biomass produced by forest growth such as deadtrees, non-merchantable trees, branches, understory, tree stumps,interplanted crops, other plants grown with trees, clippings, loggingresidue, stems, wood chips, or other similar material. Forest biomasshas the potential for use in countless different applications includingbut not limited to generating heat, production of liquid fuel,production of biogas, generating bioelectricity, and production offeedstock for chemicals and other materials.

Some forestry companies have experimented with interplantingregenerating lignocellulosic energy crops with various types of treescrops for producing forest biomass. See, for example, U.S. Pat. No.7,412,932, the disclosure of which is hereby incorporated by referenceherein in its entirety. As the demand for alternative energy sourcescontinues to increase, there is also an increasing demand for new andinnovative methods and equipment for producing forest biomass inconjunction with timberlands. Conventional agriculture equipment andmethods are often not appropriate for the rough terrain (e.g., humps andswales), stumps, sticks, and other debris encountered in forestryoperations. At the same time, the demands of modern forestry requirethat timberlands be managed at intense levels so as to produce maximumgrowth in the shortest period of time. Many of these intense practicescan have a negative impact on soil, water quality, and greenhouse gasemissions. Accordingly, there is a need to develop new silviculturepractices to enable growth of energy crops in conjunction with othercrops whilst minimizing negative impacts on the environment.

SUMMARY

The following summary is provided for the benefit of the reader only andis not intended to limit in any way the invention as set forth by theclaims. The present disclosure is directed generally towards methods forinterplanting energy crops with a primary crop on a plantation site.

In some embodiments, the present disclosure includes methods forpreparing a plantation site for planting an energy crop. Plantationsites according to the disclosure may include a primary crop planted ina first row and in a second row, the first row being separated by anintermediate area. The primary crop may be planted using uniform spacingor non-uniform spacing. The intermediate area is divided into a centerportion and two side portions (a first side portion and a second sideportion). Methods according to embodiments of the disclosure includelifting a soil and plantation debris mixture from the intermediate areaand redepositing a soil component of the soil and plantation debrismixture in the intermediate area. In some embodiments, the soilcomponent may be redeposited primarily into the center portion in theintermediate area.

Further aspects of the disclosure are directed towards methods forinterplanting an energy crop with the primary crop. In some embodiments,the primary crop is a tree crop and the energy crop is a regeneratingcrop harvested for the production of heat, electric power, othercombustible power, and/or for conversion to transportation fuels andother useful energy products. Such methods may be performed after theplantation site has been prepared according to the preparation methodsdescribed.

In accordance with another embodiment of the present disclosure, amethod for interplanting a primary crop and an energy crop on aplantation site is provided. The method generally includes planting theprimary crop in a first row, a second row, and a third row, wherein thefirst row and the second row are separated by a first intermediate area,the first intermediate area being divided into a first center portion, afirst side portion, and a second side portion, and wherein the secondrow and the third row are separated by a second intermediate area, thesecond intermediate area being divided into a second center portion, athird side portion, and a fourth side portion; preparing the firstintermediate area for planting the energy crop by: lifting a first soiland plantation debris mixture from the first intermediate area, thefirst soil and plantation debris mixture comprising a first soilcomponent and a first plantation debris component; redepositing thefirst soil component into the first intermediate area primarily in thefirst center portion; and planting the energy crop in the firstintermediate area.

In accordance with another embodiment of the present disclosure, amethod for preparing a plantation site for planting an energy crop, theplantation site having a primary crop planted in a first row and in asecond row, the first row and the second row being separated by anintermediate area is provided. The method includes (a) lifting a soiland plantation debris mixture from the intermediate area, the soil andplantation debris mixture comprising a soil component and a plantationdebris component; (b) redepositing the soil component into theintermediate area primarily in a center portion; and (c) leveling theintermediate area.

DESCRIPTION OF THE DRAWINGS

The present disclosure is better understood by reading the followingdescription of non-limitative embodiments with reference to the attacheddrawings wherein like parts of each of the figures are identified by thesame reference characters, and are briefly described as follows:

FIG. 1 is a plan view of a plot of land after plantation of a primarycrop according to embodiments of the disclosure;

FIG. 2 is a plan view of the plot of land from FIG. 1 after the primarycrop has been allowed to grow for a period of time;

FIG. 3 is a plan view of the plot of land from FIG. 2 showing a soil andplantation debris mixture;

FIG. 4 is a plan view of the plot of land from FIG. 3 showing anexemplary distribution of a soil component and a plantation debriscomponent according to embodiments of the disclosure;

FIG. 5 is a plan view of the plot of land from FIG. 3 showing anexemplary distribution of a soil component and a plantation debriscomponent according to embodiments of the disclosure; and

FIG. 6 is a plan view of the plot of land from FIG. 3 after the plantingof an energy crop.

DETAILED DESCRIPTION

The present disclosure describes methods for interplanting energy cropswith a primary crop on a plantation site. Certain specific details areset forth in the following description and FIGS. 1-6 to provide athorough understanding of various embodiments of the disclosure.Well-known structures, systems, and methods often associated with suchsystems have not been shown or described in detail to avoidunnecessarily obscuring the description of various embodiments of thedisclosure. In addition, those of ordinary skill in the relevant artwill understand that additional embodiments of the disclosure may bepracticed without several of the details described below.

In this disclosure, the term “plantation site” is used to refer to anestablished forest, farm, or estate where a crop is grown. The term“primary crop” is used to refer to any type of tree crop known to aperson of ordinary skill in the art. The term “energy crop” is used torefer to a regenerating crop harvested for the production of heat,electric power, other combustible power, and/or for conversion totransportation fuels and other useful energy products (e.g., ethanol).The term “plantation debris” is used to refer to any debris commonlyencountered in forest operations including but not limited to stumps,sticks, twigs, and root balls.

FIGS. 1-6 show plan views of a plot of land 100 on a plantation siteover various time periods as it is treated and managed using methodsaccording to embodiments of the disclosure. Referring to FIG. 1, aprimary crop 102 may be planted in a first row 104, in a second row 106,and in a third row 108 on the plot 100. It should be appreciated thatthe number of crop units (e.g., trees) of the primary crop 102 plantedand the number of rows seen in FIGS. 1-6 are merely for illustrativepurposes. In that regard, the number of crop units in a row and thenumber of rows in a plot can be configured in a repeating pattern overany sized area, such as one or more acres of land.

In the illustrated example in FIG. 1 and in other examples throughoutthe disclosure, the primary crop 102 is shown as a tree crop. Tree cropsaccording to the disclosure may include trees in any growth state,including, but not limited to, trees, tree seedlings, rooted cuttings,and tree seeds. As a non-limiting example, the tree crop may include asingle species of trees (e.g., a single species of softwood or a singlespecies of hardwood) or multiple species for forest diversity.

Examples of suitable softwood trees include, but are not limited to, thefollowing: pine trees, such as loblolly pine, jack pine, Caribbean pine,lodgepole pine, shortleaf pine, slash pine, Honduran pine, Masson'spine, Sumatran pine, western white pine, egg-cone pine, longleaf pine,patula pine, maritime pine, ponderosa pine, Monterey pine, red pine,eastern white pine, Scots pine, araucaria tress; fir trees, such asDouglas fir; and hemlock trees, including any hybrids of any of theforegoing. Suitable softwood species for a plot of land used with themethods described herein are dependent upon desired wood products, aswell as environmental and geographic factors.

Examples of suitable hardwood trees include, but are not limited to, thefollowing: eucalyptus trees, such as Dunn's white gum, Tasmanianbluegum, rose gum, Sydney bluegum, Timor white gum, and the E.urograndis hybrid; populus trees, such as eastern cottonwood, bigtoothaspen, quaking aspen, and black cottonwood; and other hardwood trees,such as red alder, Sweetgum, tulip tree, Oregon ash, green ash, andwillow, including any hybrids of any of the foregoing. Suitable hardwoodspecies for a plot of land used with methods described herein aredependent upon desired wood products, as well as environmental andgeographic factors.

Referring back to FIG. 1, the first row 104 and the second row 106 areshown separated by a first intermediate area 110 having a first widthW1. The second row 106 and the third row 108 are shown separated by asecond intermediate area 112 having a second width W2. Although FIG. 1shows the first width W1 and the second width W2 to be approximatelyequal in size, if a non-uniform row spacing is selected, the first widthW1 and the second width W2 may be substantially different.

The spacing between the rows (and accordingly the width of therespective intermediate areas) may be selected based on multiplefactors. For example, the spacing may be selected to provide for largemachinery and equipment to access the primary crop 102. The spacing mayalso be determined to provide space for activities for managing treegrowth such as fertilization, vegetation and pest control, thinning,pruning, and harvesting. The size of the trees in the primary crop 102at various stages of maturity may also be factored into the spacingselection. In some embodiments, the row spacing may be selected tooptimize the combined revenues of the primary crop 102 and an energycrop interplanted with the primary crop 102. Other considerations forthe determination of row spacing include, for example, sunlightrestrictions, hydrology, wildlife, biodiversity, and environmentalimpact on the land.

In some embodiments, the width of the first intermediate space 110(e.g., the first width W1) may be between about 15 and about 25 feet. Inan exemplary embodiment, the first width W1 may be at least about 18feet and the width of the second intermediate space 112 (e.g., thesecond width W2) may be at least about 15 feet. In other embodiments,the first width W1 may be at least about 20 feet and the second width W2may be at least about 18 feet. Additionally, in some embodiments thesecond width W2 may be greater than the first width W1. In situationswhere uniform row spacing is selected, the first width W1 and the secondwidth W2 may be substantially equal. It should be appreciated that rowspacing reasonably above or below these ranges is within the scope ofthis disclosure.

Referring to FIG. 2, a plan view of the plot of land 100 on a plantationsite is shown after the primary crop 102 has been allowed to grow for aperiod of time. In some embodiments, the intermediate area 110 may beestablished at the same time that the primary crop 102 is planted. Forexample, the rows for the primary crop 102 may be prepared, theintermediate area may be prepared, and then the both the primary crop102 and the energy crop 602 may be planted. In some embodiments, theprimary crop may be permitted to grow for about 2 to about 3 years. Inother embodiments, this time may be determined based on other factorssuch as the tree species and surrounding environment. The primary crop102 and the energy crop 602 may also be planted at the same time toprovide maximum exposure to light for the energy crop 602 before theprimary crop 102 gets large enough to shade the energy crop 602. In someembodiments the energy crop 602 may be planted after the primary crop102 has been thinned and some of the trees removed to allow for morelight. Generally, this may occur around age 10 to about 15. After theprimary crop 102 has reached the desired maturity, the plot 100 may nowbe prepared for interplanting of an energy crop.

For purposes of illustrating methods according to the disclosure, FIG. 2shows the first intermediate area 110 divided into three portions: afirst center portion 202 having a third width W3, a first side portion204 having a fourth width W4, and a second side portion 206 having afifth width W5. Likewise, the second intermediate area 112 is showndivided into three portions: a second center portion 208 having a sixthwidth W6, a third side portion 210 having a seventh width W7, and afourth side portion 212 having an eighth width W8. In some embodiments,the three portions in which the intermediate areas are divided may havesubstantially the same width. In other embodiments, the center portionmay be substantially larger than the side portions. In a non-limitingexample, W1 may be approximately 20 feet, W3 may be approximately 10feet, W4 may be approximately 5 feet, and W5 may be approximately 5feet. In another non-limiting example, W1 may be approximately 30 feet,W3 may be approximately 20 feet, W4 may be approximately 5 feet, and W5may be approximately 5 feet. Additionally W1, W2, W3, W4, and W5 mayhave any intermediate values between the above-stated ranges. Further,the side portions may be different sizes.

According to embodiments of the disclosure, preparation of theplantation site includes performing a series of steps aimed at makingthe first intermediate area 110 and the second intermediate area 112more suitable for planting energy crops. To simplify explanation, thefollowing portion of the disclosure will describe such methods withreference to the first intermediate area 110; however, it should beunderstood that substantially the same steps may be performed on thesecond intermediate area 112. A person of ordinary skill in the art willalso appreciate that the first intermediate area 110 and the secondintermediate area 112 may be prepared according to embodiments of thedisclosure at the same time or at different times.

Referring to FIGS. 3-6, preparation methods according to embodiments ofthe disclosure are illustrated. FIG. 3 shows the plot 100 covered in asoil and plantation debris mixture 302. The soil and plantation debrismixture 302 will naturally be present on the plot 100 as a result of theplantation, growth, and/or harvest of the primary crop 102. In someembodiments, the soil and plantation debris mixture 302 may be left overfrom the previous plantation harvest. The soil and plantation debrismixture 302 may consist of a soil component 304 and a plantation debriscomponent 306 in any proportion. The soil component 304 is primarilysoil (e.g., the superficial unconsolidated and usually weathered part ofthe mantle of the planer). The plantation debris component 306 isprimarily plantation debris (e.g., any debris commonly encountered inforest operations including but not limited to stumps, sticks, twigs,and root balls). A person of ordinary skill in the art will appreciatethat in many situations, the soil component 302 is not 100% soil and theplantation debris component is not 100% plantation debris. Further, insome embodiments, the soil component 304 may include a small portion ofplantation debris and the plantation debris component 306 may include asmall portion of soil.

Referring back to FIG. 3, methods according to embodiments of thedisclosure may include two primary steps: lifting and redeposition. Thelifting step may include lifting the soil and plantation debris mixture302 from the plot 100. In some embodiments, lifting the soil andplantation debris mixture 302 may be performed by moving equipment inthe first intermediate area 110 in a direction that is substantiallyparallel with the primary crop 102. Depending on the type of equipmentused, the lifting step may be relatively brief or may consume a moresubstantial period of time. The scope of the present disclosure shouldnot be limited in any manner that would require lifting of a minimum ormaximum height or distance.

After lifting, the soil and plantation debris mixture 302 may beredeposited onto the plot of land 100. Conventional redepositiontechniques generally aim to push soil towards the primary crop 102 inorder to encourage growth of the primary crop 102. In embodimentsaccording to the disclosure, the soil and plantation debris mixture 302is redeposited primarily into the first intermediate area 110, butdistribution within the first intermediate area 110 considers enablinggrowth of an interplanted energy crop as well as the growth of theprimary crop 102. For example, the soil component 304 may be directedaway from the primary crop 102 during redeposition in order to preparethe first intermediate area 110 for planting of the energy crop. Asshown in FIG. 4, the soil component 302 may be redeposited primarilyinto the first center portion 202. In some embodiments (e.g., as shownin FIG. 4), the plantation debris component 306 may be redepositedprimarily into the first side portion 204 and/or the second side portion206.

In some embodiments, the exact distribution and manner in which the soiland plantation debris mixture 302 may be redeposited within the firstintermediate area 110 may vary. In FIG. 5, for example, the majority ofthe soil component 304 is shown deposited in the first center portion202; however, there is a small amount of soil component 304 present inthe first side portion 204 and in the second side portion 206. Inaddition, substantially more of the plantation debris component 306 maybe present in the first side portion 204 compared with the second sideportion 206. In some embodiments, all or substantially all of theplantation debris component 306 may be redeposited into the first sideportion 204. In some embodiments, 100% of a portion of a component thatis lifted may not necessarily be redeposited. In some embodiments, aportion of the soil and plantation debris component 302 lifted from thefirst intermediate area 110 may be redeposited onto the secondintermediate area 112. A person of ordinary skill in the art willappreciate that many variations of distributions are within the scope ofthe disclosure, but that it would be exhaustive to explain each one indetail.

In some embodiments, various additional steps may be performed with thesteps discussed above. For example, an intermediate filtering step maybe performed before the soil component 304 and the plantation debriscomponent 306 are redeposited. In a non-limiting example, filtering mayinclude separating the soil and plantation debris mixture 302 into asoil component 304 and a plantation debris component 306. A screen,filter, or any other equipment known to a person of ordinary skill inthe art that is suitable for separating materials may be used toaccomplish filtering.

In some embodiments, a leveling step may be performed on the firstintermediate area 110 after redeposition of the soil component 304 andthe plantation debris component 306. Leveling may be effective to changethe slope of the terrain of the plot of land 100 to make it moresuitable (e.g., more flat) for planting and growing energy crops. Thismay be accomplished using grader blades, grading trucks, or any otherequipment known to a person of ordinary skill in the art. The result isa relatively flat strip with exposed mineral soil and relatively fewstumps, root balls, or other debris that may cause problems whileplanting a crop.

One non-limiting example of a conventional piece of equipment suitablefor use with methods according to the disclosure is a machine commonlyreferred to as a V-shear implement. V-shear implements may be attachedto a tractor and pushed across the first intermediate space 110 toperform the lifting, deposition, and filtering steps described above. Insome embodiments, standard V-shear implements may be configured so thatthe device's blade is operated just below the surface of the soil on theplot 100. Accordingly, plantation debris may be redeposited to the sideportions (e.g., the first side portion 204 and the second side portion206) of the first intermediate area 110 as the V-shear moves. At thesame time, minor humps and swales in the plot's terrain may be alsosmoothed. According to embodiments of the disclosure, conventionalV-shear equipment may be operated in any manner suitable to minimizemovement of the soil component 304 to the side portions (e.g., the firstside portion 204 and the second side portion 206) of the firstintermediate area 110.

In addition to conventional equipment, methods according to embodimentsof the disclosure may also be performed with other non-conventional, butsuitable equipment. One non-limiting example of such equipment includessoil treating systems, shear assemblies, and other devices described inU.S. application Ser. No. 13/309214, filed Dec. 1, 2011, and titled“Soil Treating System and Shearing Assembly.” A person of ordinary skillin the art will also appreciate that other types of equipment notexplicitly mentioned in this disclosure may be used to perform the stepsof methods described herein.

In some embodiments, a single piece of equipment may be used to performone step in methods according to the disclosure. For example, the samepiece of equipment may be used for lifting, redepositing, and filtering.In other embodiments, the same piece of equipment may be used forlifting, redepositing, filtering, and leveling. In other embodiments,different pieces of equipment may be used to perform any combination ofdifferent steps.

After preparation of the plot 100 according to methods described above,energy crops may be interplanted with the primary crop. FIG. 6 showsenergy crops 602 planted in the first intermediate area 110. Forclarity, the distribution of the soil component(s) 304 and plantationdebris component(s) 306 is not shown in FIG. 6. Suitable energy crops602 are regenerating lignocellulosic energy crops, including perennialplant species such as switch grass (including panicum virgatum and othervarieties of the genus panicum), miscanthus (including miscanthusgiganteus and other varieties of the genus miscanthus), giant reed(arundo donax), energy cane (saccharum spp.), and napier grass(pennisetum purpureum). These energy crops are grown for the specificpurpose of producing energy from all or part of the resulting plant. Asnon-limiting examples, switch grass and miscanthus are energy crops thatregenerate naturally following a full periodic harvest, for example, anannual harvest.

Methods according to the embodiments of the disclosure align the cost ofplanting a long-term primary crop with the economic returns ofharvesting a combination of the primary crop and the energy crop. Inembodiments where the primary crop is a tree crop, the primary crop maybe harvested to make wood products such as lumber, wood chips, pulp forcellulosic products, etc. The energy crops may be harvested asappropriate for the production of heat, electric power, othercombustible power, and/or for conversion to transportation fuels andother useful energy products. Accordingly, methods according to thedisclosure include periodically harvesting the energy crop as well asharvesting the primary crop. In some embodiments, systems and methodsaccording to the disclosure are expected to reduce the amount of tillagenecessary for such harvesting.

Words in the above disclosure using the singular or plural number mayalso include the plural or singular number, respectively. For example,use of the term “soil component” could also apply to and “soilcomponents.” Likewise, use the term “crop” could also apply to and“crops.”

While the plot of land 100 in the illustrated embodiments of FIGS. 1-6is shown to be planted with at least two crops: a primary crop 102 andan energy crop 602, it should be appreciated that planting the plot ofland 100 with more than two crops is also within the scope of thepresent disclosure. Further, specific types of crops not explicitlydisclosed that would be obvious to a person of ordinary skill in the artare envisioned to be within the scope of the disclosure.

From the foregoing, it will be appreciated that the specific embodimentsof the disclosure have been described herein for purposes ofillustration, but that various modifications may be made withoutdeviating from the disclosure. For example, dimensions of theintermediate portions and side portions specified in this disclosure maybe modified given tolerances acceptable to a person of ordinary skill inthe art. Additionally, methods according to the disclosure may be usedwith equipment not explicitly described provided that such equipment issuitable for use. Aspects of the disclosure described in the context ofparticular embodiments may be combined or eliminated in otherembodiments. For example, aspects relating to embodiments where theprimary crop is planted using uniform spacing may be combined oreliminated with aspects relating to embodiments where the primary cropis planted using non-uniform spacing. Further, while advantagesassociated with certain embodiments of the disclosure may have beendescribed in the context of those embodiments, other embodiments mayalso exhibit such advantages, and not all embodiments need necessarilyexhibit such advantages to fall within the scope of the disclosure.Accordingly, the invention is not limited except as by the appendedclaims.

While illustrative embodiments have been illustrated and described, itwill be appreciated that various changes can be made therein withoutdeparting from the spirit and scope of the invention.

1. A method for interplanting a primary crop and an energy crop on aplantation site, the method comprising: planting the primary crop in afirst row and a second row, the first row and the second row beingseparated by an intermediate area, the intermediate area being dividedinto a center portion, a first side portion, and a second side portion;preparing the plantation site for planting the energy crop by: lifting asoil and plantation debris mixture from the intermediate area, the soiland plantation debris mixture comprising a soil component and aplantation debris component; redepositing the soil component onto theintermediate area; and planting the energy crop in the intermediatearea.
 2. The method of claim 1, further comprising allowing the primarycrop to grow for a period of time before preparing the plantation sitefor planting the energy crop.
 3. The method of claim 1, furthercomprising leveling the intermediate area after redepositing the soilcomponent.
 4. The method of claim 1, further comprising filtering thesoil and plantation debris mixture to separate the soil component fromthe plantation debris component.
 5. The method of claim 1, wherein theintermediate area is about 18 feet to about 20 feet wide.
 6. The methodof claim 1, wherein the center portion of the intermediate area is about9 feet to about 10 feet wide.
 7. The method of claim 1, wherein theenergy crop is switch grass.
 8. The method of claim 1, wherein theprimary crop is a tree crop.
 9. A method for interplanting a primarycrop and an energy crop on a plantation site, the method comprising:planting the primary crop in a first row, a second row, and a third row;wherein the first row and the second row are separated by a firstintermediate area, the first intermediate area being divided into afirst center portion, a first side portion, and a second side portion;and wherein the second row and the third row are separated by a secondintermediate area, the second intermediate area being divided into asecond center portion, a third side portion, and a fourth side portion;preparing the first intermediate area for planting the energy crop by:lifting a first soil and plantation debris mixture from the firstintermediate area, the first soil and plantation debris mixturecomprising a first soil component and a first plantation debriscomponent; redepositing the first soil component into the firstintermediate area primarily in the first center portion; and plantingthe energy crop in the first intermediate area.
 10. The method of claim9, further comprising allowing the primary crop to grow for a period oftime before preparing the plantation site for planting the energy crop.11. The method of claim 9, further comprising: preparing the secondintermediate area for planting the energy crop by: lifting a second soiland plantation debris mixture from the second intermediate area, thesecond soil and plantation debris mixture comprising a second soilcomponent and a second plantation debris component; redepositing thesecond soil component into the second intermediate area primarily in thesecond center portion; and planting the energy crop in the secondintermediate area.
 12. The method of claim 9, wherein the firstintermediate area has a first width and the second intermediate area hasa second width, the first width being greater than the second width. 13.The method of claim 12, further comprising: leveling the firstintermediate area after redepositing; and leveling the secondintermediate area after redepositing.
 14. A method for preparing aplantation site for planting an energy crop, the plantation site havinga primary crop planted in a first row and in a second row, the first rowand the second row being separated by an intermediate area, the methodcomprising: (a) lifting a soil and plantation debris mixture from theintermediate area, the soil and plantation debris mixture comprising asoil component and a plantation debris component; (b) redepositing thesoil component into the intermediate area primarily in a center portion;and (c) leveling the intermediate area.
 15. The method of claim 14,further comprising filtering the soil and plantation debris mixture toseparate the soil component from the plantation component.
 16. Themethod of claim 14, wherein the intermediate area is at least about 18feet wide.
 17. The method of claim 14, wherein the primary crop is atree crop.
 18. The method of claim 14, wherein lifting the soil andplantation debris mixture from the intermediate area is performed by ashear assembly attached to a prime mover or tractor.
 19. The method ofclaim 14, wherein lifting the soil and plantation debris mixture fromthe intermediate area comprises moving a shear assembly having asubstantially V-shaped serrated cutting blade across the intermediatearea.